Two cells of the same e.m.f. e but different internal resistances,R1 and R2, are connected in series with an external resistance R. The potential drop across the first cell is found to be zero. The external resistance R [Fig.] is
see full answer
Your Exam Success, Personally Taken Care Of
1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya
a
r1 - r2
b
r1 / r2
c
r1 r2
d
r1 + r2
answer is A.
(Unlock A.I Detailed Solution for FREE)
Best Courses for You
JEE
NEET
Foundation JEE
Foundation NEET
CBSE
Detailed Solution
Current i in the circuit=2e/r1+r2+RVoltage drop across Ist cell=V1=e−ir1∴ V1=e−2er1R+r1+r2=0∴ e=2er1R+r1+r2 or R+r1+r2=2r1R=r1−r2